Onset of rocuronium-induced neuromuscular block evaluated subjectively and accerelomyographically at the masseter muscle

Abstract

Subjective evaluation of contractions of the MM by an anesthesiologist's hand may be reliable to determine faster timing for safe tracheal intubation.

Comparison of four facial muscles, orbicularis oculi, corrugator supercilii, masseter or mylohyoid, as best predictor of good conditions for intubation

“…[4][5][6]12,19 Although it remains the 'gold standard' for many anaesthesiologists, this study did not compare the onset of neuromuscular block at the facial muscles with the adductor pollicis due to the slower onset time. [4][5][6]12,19 Although it remains the 'gold standard' for many anaesthesiologists, this study did not compare the onset of neuromuscular block at the facial muscles with the adductor pollicis due to the slower onset time.…”

“…2 Acceleromyographic estimation at the corrugator supercilii allows for a better correlation between the time of onset and the degree of neuromuscular blockade at the laryngeal adductor muscles. 6,7 Unfortunately, the acceleromyographic monitoring in these studies was performed during a steady state of general anaesthesia after laryngeal mask insertion, not before tracheal intubation. 4,5 We also observed a difference between the orbicularis oculi (80%) and corrugator supercilii (92%) in the incidence of 'clinically acceptable' intubation conditions after 0.6 mg kg À1 of rocuronium, even though this did not reach significance.…”

“…An acceleromyographic transducer was placed at a point inferior to the zygomatic arch and anterior to the mandibular condyle to record the movement of the masseter (A) 6 and another at a point posterior to the mandibular condyle to record the movement of the mylohyoid (B). An additional patient was added to each group to account for dropouts.…”

“…2 An alternative is the corrugator supercilii, which gives a better reflection of the development and degree of neuromuscular blockade of the larynx and diaphragm. 6,7 A study of dysphagia that investigated the movements elicited by electrical stimulation of the mylohyoid muscle identified depression of the mandible and elevation of the hyoid bone, the floor of the oral cavity and the tongue. 4,5 Monitoring masseter contractions during mandibular nerve stimulation has also been shown to be a clinically reliable method for identifying the onset of neuromuscular blockade, and enabling faster, safer tracheal intubation.…”

Rocuronium pharmacokinetics and pharmacodynamics in the adductor pollicis and masseter muscles

“…1,[8][9][10][11] In contrast to other central muscles, the masseter muscle is relatively more sensitive to neuromuscular blocking drugs (NMBD) demonstrated using mechanomyography or acceleromyography. 1,[8][9][10][11] In contrast to other central muscles, the masseter muscle is relatively more sensitive to neuromuscular blocking drugs (NMBD) demonstrated using mechanomyography or acceleromyography.…”